Messages - Sporgon

And before you post a comment about how "All professional quality lenses have metal mounts" read this post on plastic mounts by Roger Cicala.

Terminology mix up: what most of us call the 'mount' Roger calls the 'bayonet', and Roger's mount is the part that the metal bayonet is attached to, which is then attached to the camera shell or chassis.

There's a lot of talk about this camera being a 5DIV. In Canon Rumors post from November, it's stated that the new high megapixel camera will come in a new line, above the 5D line, which makes sense to me. The 5D3 is pretty much the ideal all-rounder camera and I can't see Canon messing with what has been a winning formula.

Such a camera would be even more of an "all-rounder" giving the reach of a 7DII, the landscape potential of medium format,and the low-light performance of a 5DIII (or better due to lower fixed pattern noise). They'd just have to find a way to get the frame rates up to the 5DIII's level or better, which should be doable, and provide some options for reducing file size in-camera (cropping, downsampling, lossy compression, etc.).

I agree with lintoni on this: the 5 series is the top end 'general purpose' camera, with the emphasis on 'event' style photography. 23 mp is high mp, that's the whole point. As private has stated, when shooting hundreds of images, even thousands maybe, massive files are a pain. SRaw etc can reduce file sizes but also slows down processing, so it's far from being an ideal solution. The true resolution that can be obtained from 23 mp on FF when each pixel is true is amazing.

Also 50 mp on FF will not give you the full potential of a larger format, because the larger format always has more magnification, larger capture and greater volume of light for the same framing.

Canon will recognise this. They probably also recognise that there are (just) enough punters out there who desire greater mp on FF than mid twenties to make it worthwhile in producing one, but it will be a separate, more specialist body. Certainly not the 5D IV.

I wanted to get Whitby Abbey at sunrise, so had to set off at three thirty in the morning in order to arrive at that time. There was a thin bank of cloud on the horizon and I had to wait for the rising sun to clear this, so the picture was taken with the sun higher than I had wanted, and I was a bit disappointed with it at first. However as time goes by and I see it with the others I think it stands up well. Glad you like it.

Thanks for posting -- love the Whitby Abbey shot. The light, and color in the sky, plus a beautiful setting and reflection to boot -- beautiful.

Thanks for that Famateur, you've made my new year evening !

As I said in the quote above I made a big effort to get that shot, but the lighting ended up not as I had imagined it was going to be. However the more I see it, especially among other pictures, the more I like it.

I wanted to get Whitby Abbey at sunrise, so had to set off at three thirty in the morning in order to arrive at that time. There was a thin bank of cloud on the horizon and I had to wait for the rising sun to clear this, so the picture was taken with the sun higher than I had wanted, and I was a bit disappointed with it at first. However as time goes by and I see it with the others I think it stands up well. Glad you like it.

The feeling of a tight fit with a small light lens is quite normal. As it is light it has little mass to overcome the friction of the mount as you turn. In comparison the effort needed to lift and turn a much heavier lens such as an 85 f1.2 is much greater; the lens has more mass and so overcomes the friction of the mount easily.

You often hear people complaining of their new 70-200 f2.8 feeling 'lose' on the mount; it's the same effect in reverse. If this lens was perceived to be as tighter fit as one like the new 24 pancake then you'd need Arnie to mount your heavier lenses for you. Not to mention the wear.

I am a fan of DualISO with ML. I prefer it to HDR with multiple shots as you can shoot moving subjects with that. Also if you are shooting against the light it works well. It works well with EC +4 and Auto ISO.

I'm quite new to ML DualISO, I'm still trying to learn how to exposure with that.

Here's one from about 2 weeks ago:

That's a great shot, perfect lighting balance, or rather in this case exposure balance. I'd just get the guy to take his fat wallet out of his back pocket next time !

As a hopefully impartial observer, could I ask you post a shot you deem critically sharp? So we have an idea what you mean. I'm intrigued how people differ on this

This is a single frame from a new pano, shot on 5DII + 40mm pancake, 1/20. f7.1, ISO 100, two second timer, mirror lock, 16 pound Manfrotto 058.

The whole picture is reduced for this website, the crop is full size. There will be some air diffusion as I was beside a river and the temperature was falling rapidly from about +5c to below freezing. However I am close enough to the subject for it not to make much difference.

The only sharpening applied to cancel out the AA is 100% of 0.3 pixel, threshold level 1. Obviously you could sharpen this as much as you wanted.

You don't need a tripod and static subjects to get little or no relevant movement during an exposure. Good technique, fast shutter speeds, and IS can all combine to get pixel-level performance equal to the best you can get in the lab, and I do it regularly. I shoot a lot of airplanes and often have final images that are 1:1 pixel crops from a crop camera with a 2x teleconverter mounted.

You are so wrong there. Granted you may; or may not. For the bayer pattern of pixels to describe everything accurately any microscopic movement and your four three colour arrays will receive confused information. Frequently the data from a hand held shot can looked clogged up - if you're going to be really picky about it, and that is infantisimal movement. IS does not produce the same data as a genuinely stable shooting platform, and remember just because it's on a tripod doesn't mean it's totally stable.

So when you say "good technique, fast shutter + IS = as good as in the lab" ( by the 'lab' I presume you mean rock steady platform etc etc.) then that statement is both misleading and wrong.

I will be shooting some single row, and possibly multiple row panoramas in a couple of months during a 3 day visit to the South Rim of the Grand Canyon. I am looking ahead as to what lenses I might use for this. Has anyone used the 100mm f/2.8L macro or the 135mm f/2L for stitched panoramas, and if so how well did they work for that? Thanks.

The 135L is great for panoramics, as long as the subject isn't too close, which it is unlikely to be when using this lens; certainly not the Grand Canyon. I'm attaching two 'double stacked' panoramics both shot on the 135L. Of all my panoramics these have a quality and brightness to them that I imagine I can see, others probably can't unless it is pointed out. As usual we are splitting hairs, but the use of longer focal lengths allow more volume of light to make the picture. This is one of the main advantages of a larger format system, the focal lengths used are longer, and they pass more volume of light for a given aperture. ( Not to be confused with light density - aka exposure). It is also one of the issues with cramming more pixels into a given format size. Pixels are only one part of the resolution; you must have light as well. Once you have enough pixels to define a subject accurately ( along with all the others factors needed to do this), then adding more pixels is very much a law of diminishing returns, so I have no desire to own a 50 mp FF sensor sized camera. Panoramic stitches on the other hand are larger format. The original picture of Beverley Minster for example was about 175 mp with a format size of about 147mm x 73, so not far off a large 5x4 format film camera.

Same thing goes for the 100L. Very low distortion = good, far out nodal point = bad. If you are shooting subjects closer to you, then the less distortion and the shorter the nodal point of the lens the better. You can easily see this for yourself if you have a short prime and a standard zoom. With say a 40 pancake, which has both very low distortion and a short nodal point, stand in the corner of a room and then, keeping the camera level, sweep around the room looking through the viewfinder, watching the wall joint to the ceiling. Now put on a standard zoom and set it to 40mm. Most standard zooms at 40 have very low distortion. Do the same thing and watch how the edges of the frame twist and bend as you sweep round. This is parallax, and your stitching software will have to try and deal with this.

As I said at the beginning, not an issue with the 135L as the subject will be well away from you.

Can anyone with a good understanding of MTF charts and actual field experience share how the three 24-70mm lenses compares to each other in terms of distortion (especially at wide end)? I have been using the 24-70mm f2.8L I for more than 4 years but sometimes borders sharpness and distortion particularly at the wide end annoy me so, I would like to know if the 24-70mm f/2.8L II or the 24-70mm f4L IS offer more controlled distortion.

Most appreciated!

At 24 mil those you mention are all pretty much the same - about 2.4 - 2.6 % according to photozone. Primes are a lot better in this respect, including extreme corner sharpness. The 24 f2.8 IS is around 0.9% distortion, but king on the hill is definitely the 24 TS-E. In fact I'm thinking of getting one of these to make my panoramic shooting easier.

There was a thread about this issue of off centre focus points about a year ago. Seems field curvature with that lens is the cause. Bit annoying really: if ever there was a lens where you needed your outer points it's a f1.2.

In theory: yes.But you run into a myriad of problems as you have to account for factors that would simply vanish in landscape photography.And then you also want to use focus stacking to actually gain from the larger sensor estate - let's hope your subjects are patient.

Agreed. Any larger format has less dof as you are using a longer lens for a given framing, but focus stacking is much easier on one frame, assuming the lens doesn't have much focus breathing. I have used FF stitching for macro shots ( not something I do much off), but my aim was to produce a shallow dof image, even then at f11 !

There are many people who like the idea of a greater mp on a FF sensor, maybe even enough to make it viable for Canon to produce one, but, as many people on this thread have pointed out, the physics of it all means we are ultimately format limited.

I agree with you here: the problem is that we are restricted by the format - unless optics and sensors become perfect and defy the laws of physics. Resolution isn't just pixels, it's requires optics and light as well, among other things. Exactly the same thing with 'reach' on crop sensors; the only thing you are increasing is the number of pixels on target, all the other major factors remain the same. This is why you don't see as much improvement from the extra numbers of pixels as you would expect, even after up sampling the cropped FF sensor. 50 mp on a FF sensor is OK as long as it doesn't come at a per-pixel cost in IQ. Of course it will come at the cost of much bigger files, and even sRAW or mRAW takes longer to process than the full file.

The other thing is that you can create a format larger than a 645z with FF by stitching. OK there are many instances when this is not practical, but given what a 645 would be used for it's as likely as not that you could use this method.

The problem is that if we are going to split hairs - and we are most of the time - then a larger format uses more light to make the image. The larger area records more light, the longer focal length lenses pass more light and magnify the subject more; the differences go on and on. More pixels are just one small part of the formula.